In contrast to the conventional radiant heat grill, hot air grill apparatus works with hot air circulation whereby the air present in the grill chamber is heated and circulate around the roast or bake goods by the hot air assembly. The food-stuff that is to be roasted, cooked, baked or grilled no longer needs to be turned and receives better, faster and more uniformly from all sides the heat necessary for roasting.
German published specification No. 25 55 522 discloses a container provided with a closure and adapted to receive food-stuff for thermal treatment by means of a hot air assembly inserted in an opening in the bottom of the container. The vertically arranged bottom of the container is removably mounted by screws on a vertical arm of an essentially L-shaped stand. The arm is fixed to a horizontal foot which extends under the fan motor and control part. The container has a removable front door which is also vertical. The container, door and adjustable height grating are removable and easily cleaned, for example in a dishwasher. The hot air assembly, on which grease and other constituents of the food being cooked may deposit by reason of the recirculation of air, is not removable and can be cleaned only with difficulty as the electric drive and control parts of the apparatus cannot be immersed in water. Layers of grease and the like deposited on the surface of the heating elements reduce the efficiency of heat conduction and thereby lengthen the grilling and roasting process. Moreover, the accummulation of grease and other deposits on the fan and all other parts of the hot air aggregate is unhygenic and unsightly. The overall dimensions of the apparatus in relation of the capacity of the grill chamber are relatively great so that the apparatus occupies a large amount of room on the kitchen table or in the cupboard and is bulky to transport. Moverover, it cannot be mounted on a wall but must stand on a table.
German published specification No. 24 12 835 discloses a hot air roasting apparatus for household use in which a motor with a fan heating element, switching and control elements are mounted on the cover of a downwardly opening hat-shaped insulating container. This hat-shaped container is set on top of a bowl containing gratings on which the food-stuff is placed. Also with this apparatus the parts of the hot air assembly can be cleaned only with difficulty. The motor stands high above the cover on which it is mounted. The bowl for the food-stuff to be heated must be placed on a heatproof surface because it has no insulation or legs. This apparatus likewise cannot be mounted on a wall but must sit on a table. The hot air assembly obscures direct view of the food so that control of its condition is difficult.
German published specification No. 24 09 370 discloses a closable container for the thermal treatment of food-stuff. The container comprising a tank part and a cover part is tiltably arranged on a foot support. An air heating and circulating device is mounted in a side wall of the container in a manner not described. The side has no opening large enough for passage of the air heating assembly which is thus not removable. With the use of wholly identical half shells which are open at one side and leave free an opening for insertion and removal of food, a cover is necessary. Also this apparatus is not of optimal form for cleaning, is insecure in the mounting and cannot be mounted on a wall. For the accommodation of foot and heating aggregate parts, these must be disassembled in a large number of small parts and put loose in the shell.
German published specification No. 24 09 292 discloses a hot air assembly for cooking food in an enclosure such as a roasting oven. The assembly consists of two groups of which one is inside the enclosure and the other is mounted outside the enclosure. The group which is outside the enclosure comprises a motor and control elements. The group that is inside the enclosure comprises a dish-shaped reflector provided with a cover and housing, a heating element and a fan which is mounted on the motor shaft which extends through the enclosure wall and through the central portion of the reflector. The fan can be removed from the shaft by unscrewing a retaining nut and the group inside the enclosure can be dismounted for cleaning, for example in a dishwashing machine. When the cover of the reflector is removed, there is the danger of injury of fingers by the fan in case the motor runs. Safety means are not provided and could be installed only with difficulty. The apparatus is not suitable for mounting on a base. It provides for heating food in a fixed enclosure such as a roasting over rather than in a removable receptacle.